|Microsurgery: Transplantation and Replantation by Harry J. Buncke, MD, et al.
Table 28-1. Simultaneous Transplants
Bilateral toes 28 Toe and other tissue flaps 16 Vascularized bone and second soft tissue flap 5 Two soft tissue flaps 11
Second-toe transplantation, as described in the section on toe transfer, has been useful in providing length to partial amputations. In patients with multiple amputations but an intact thumb, second-toe transplants are usually applied to the ulnar aspect of the hand, to maximize opposition and broad grasp. In patients who have suffered thumb loss as well as other digital amputations, the great toe is used for restoration of the thumb, combined with simultaneous or subsequent transplantation of the contralateral second or second and third toes. Ipsilateral greatand second-toe transplantation has been avoided to limit donor-site problems.
The vascular hookups with and without interpositional grafts may be complex and require careful planning. Vein grafts are used freely and are always autogenous because synthetic materials and preserved vascular grafts do not have dependable patency rates at internal diameters of 2 mm or less.14 Although larger vessels with a higher pressure head remain patent, smaller vessels cannot tolerate the platelet aggregates and laminated fibrin clots that form at the junctions and on the surface of these nonautogenous anastomoses. 15 A simple but important point to keep in mind when dealing with autogenous vein grafts is the orientation of the graft. The proximal and distal ends must always be clearly identified and preserved. Our custom is to mark the proximal end with a purple marking pen (i.e., purple = proximal).3 When multiple grafts are taken from the same vein, the proximal end must be clearly remarked on each segment. Although these points seem obvious, they may be overlooked during a complex procedure with multiple teams working simultaneously and in sequence. Internal shunts to provide vascular flow can be performed between different simultaneous transplants, or to augment flow between areas of multi-component transplants, rather than relying on inconsistent perforators. One of the first internal shunts we used was to connect the superficial circumflex iliac artery (SCIA) system of the groin flap to the deep circumflex iliac artery (DCIA) vessels of the underlying iliac crest. Anastomosis of the SCIA vessels to side branches of the DCIA system provides increased perfusion and improved venous drainage to the overlying skin island when transferring the bone and skin island together. Branches of the deep system, if left long, can also provide arterial inflow for a second simultaneous skin, bone, or toe transplant. The vascular anatomy of the first metatarsal space, outlined in the toe and neurovascular island chapters, is also ideally suited for multiple transplants. With the dominant superficial first metatarsal system (SFMS), the consistent communicating branch to the deep first metatarsal system (DFMS) found at the base of the first metatarsal space can be cut long and used to perfuse an adjacent toe transplant harvested from the opposite foot. Venous branches in the metatarsal system are numerous, and can be easily used to accept venous drainage from a second toe transplant. Caution must be used on the venous side because valves exist at almost every branching point, and proper orientation must be preserved. It is not wise to use Y-connections in vein grafts to the arterial system because at least one branch will be blocked by a valve. Although there are few sources outside of omentum, arterial grafts may be required in this situation. 15,16
Other arterial networks suitable for acceptance of simultaneous transplant include the thoracodorsal pedicle, which provides multiple long vessels for internal shunting to an additional transplant. As Nassif and Baudet have pointed out, the entire subscapular vascular system can be chained together like a string of beads to include the scapular skin island and the lateral border of the scapula carried on the circumflex branch. In combination with the thoracodorsal vessels, the latissimus dorsi with or without its skin paddle, the serratus, and segments of skin or rib can be included.17 The use of the serratus branch T-connection on the thorocodorsal pedicle of the latissimus muscle as an interpositional graft was described by Godina some years ago.18 He inserted the T-connection into damaged lower extremity vessels, re-establishing distal perfusion of the extremity while supplying the muscle cover of the latissimus. Both the peroneal artery of the fibula and the radial artery of the radial forearm flap can be interposed in a similar fashion into a recipient arterial system to provide arterial flow to other free transplants as a "flow-through" flap.l0 Again, Baudet has pointed out that half of the soleus muscle can be transplanted with the fibular on branches from the peroneal artery.19 Zhong-Wei and others have transplanted a skin island with the fibula based on septocutaneous branches of the peroneal artery. 20
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